This proposal is an extension of ongoing work in our laboratories involving the computer-assisted collection and analysis of quantitative data from Golgi-type preparations of normal aged and demented human brain. Neurons will be sampled from the parahippocampal gyrus, somatomotor cortex, inferior olivary nucleus and the locus coeruleus. Tissues will be taken at autopsy from individuals ranging in age from 18 to 95 years or older. Cases will be selected to represent neurologic and neuropathologic normalcy as well as presenile dementia of the Alzheimer's type.